Method of casting an aluminum engine



Dec. 13, 1966 A. c. SAMPIETRO ETAL 3,290,749

METHOD OF CASTING AN ALUMINUM ENGINE Original Filed Aug. 17. 1961 I 8Sheets-Sheet l 13, 1966 A. c. SAMPIETRO ETAL. 3,290,740

METHOD OF CASTING AN ALUMINUM ENGINE Original Filed Aug. 17. 1961 aSheets-Sheet 2 INVENTOR6- baa/417% 6 547728590.

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A- C. SAMPIETRO ETAL METHOD OF CASTING AN ALUMINUM ENGINE 8 Sheets-Sheet5 Original Filed Aug. 1'7. 1961 o //4 mi 6 m fw m WWW aw Z w 6 J6 JWWW 4Dec. 13, 1966 A. C. SAMPIETRO ETAL METHOD OF CASTING AN ALUMINUM ENGINEori inal Filed Aug. 17. 1961 8 Sheets-Sheet 4- 1 VENTORJ ZM N p Dec. 13,1966 A. C.$AMPIETRO ETAL 3,299,749

1 METHOD OF CASTING AN ALUMINUM ENGINE Original Filed Aug. 17. 1961 8Sheets-Sheet 5 Dec. 13, 1966 A. c. SAMPI'ETRO ETAL 3,290,740

METHOD OF CASTING AN ALUMINUM ENGINE 8 Sheets-Sheet 7 Original FiledAug. 17. 1961 g i M W 3 \\\\W.

,1966 A. c. SAMPIETRO ETAL 3, 90,740

METHOD OF CASTING AN ALUMINUM ENGINE Original Filed Aug. 17. 1961 8Sheets-Sheet 8 IN V EN TORJ.

United States Patent 3,290,740 METHOD OF CASTING AN ALUMINUM ENGINEAchilles C. Sampietro, Bloomfield Hills, and Kenneth G. Matthews, GrossePointe Woods, Mich., assignors to Kaiser Jeep Corporation, a corporationof Nevada Original application Aug. 17, 1961, Ser. No. 132,226, nowPatent No. 3,173,407, dated Mar. 16, 1965. Divided and this applicationMar. 15, 1965, Ser. No. 442,852 6 Claims. (Cl. 22200) This applicationis a divisional application of the copending application of Achilles C.Sampietro et al., Serial No. 132,226, filed August 17, 1961, now PatentNo. 3,173,407, issued March 16, 1965.

This invention relates to an improved construction and method ofmanufacture for an internal combustion engine.

The internal combustion engine of this invention utilizes an engineblock constructed of an aluminum alloy or an alloy of some similarlightweight metal such as magnesium. When constructing an engine blockof an aluminum alloy, it is desirable that structural threadedconnections with the block be eliminated since such threads do not havethe strength of similar threads in a block made of some ferrous metal,such as cast iron; therefore, it is an object of this invention toprovide an internal combustion engine having an engine block of analuminum alloy or the like whereby structural connections to thealuminum block by means of threads in the block are eliminated and inwhich structural connections are made by means independent of the blockmaterial.

It is also desirable in an internal combustion engine having an engineblock of an aluminum alloy or the like that the construction be suchthat the cylinder walls should not be used as a load-carrying member forloads relative to the cylinder head and the engine block. With such aconstruction, the wall thickness of the cylinder walls can be held to aminimum, thereby realizing a savings in weight and material and, hence,cost.

It is current practice to die cast engine blocks of aluminum alloy bypulling the die out from the top of the cylinder bores and casting atthe same time vertical Walls to constitute the water jacket. By so diecasting, the minimum thickness of the water jacket walls and cylinderwalls is determined by die casting procedures inherent in that method ofdie casting. Therefore, it is an object of this invention to provide anovel method for die casting an engine block of an aluminum alloy havinga construction permitting the formation of thinner cylinder walls andthe use of a water jacket of thinner wall construction.

In many engine constructions it is also required that the water jacketwalls themselves be load-carrying members and thus be of suflicientstrength, and hence, thickness, to so carry a load.

Other objects, features, and advantages of the present invention willbecome apparent from the subsequent description and the appended claims,taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a side elevational View with some parts broken away and someparts shown in section of an engine assembly embodying the features ofthis invention;

FIGURE 2 is a sectional view taken substantially along the line 22 ofFIGURE 1;

FIGURE 3 is a sectional view taken substantially along the line 33 ofFIGURE 1;

FIGURE 4 is a fragmentary top elevational view of the engine block shownin the engine assembly of FIG- URE 1;

- FIGURE 5 is a fragmentary view, with one portion of the engine blockof FIGURES 1-4 shown in section, depicting the die castin g of thatengine block;

FIGURE 6 is a fragmentary view showing a different 3,290,746 PatentedDec. 13, 1966 Nice portion of the engine block as shown in FIGURES 1-4in the die casting of that engine block;

FIGURE 7 is a front elevational view, with some parts in section andsome parts shown broken away, of a modified engine assembly embodyingsome of the features of this invention;

FIGURE 8 is a fragmentary top elevational view of the engine block ofthe engine assembly shown in FIG- URE 7;

FIGURE 9 is a fragmentary view, with one portion of the engine block ofFIGURES 7 and 8 shown in section, depicting the die casting of thatengine block;

FIGURE 10 is a fragmentary view showing a different portion of theengine block as shown in FIGURES 7 and 8 in the die casting of thatengine block; and

FIGURE 11 is a front elevational view with some parts in section andsome parts shown broken away of another modified engine assemblyembodying some of the features of this invention.

While this invention is shown specifically in conjunction with anin-line six cylinder engine, it is to be understood that the principlesas set forth are not necessarily restricted to that type of engine.

Looking now to FIGURES 1-4, an internal combustion engine, generallydesignated by the numeral 20, comprises a cylinder head assembly 22, anengine block assembly 24, and a plurality of bearing block assemblies26, all vertically joined or clamped together in a sandwich-typearrangement by means of a plurality of studs. The studs are threaded atopposite extremities and the sandwich is clamped together by tighteningnuts disposed at each extremity. The studs represent the primary meansby which the cylinder head assembly 22, the engine block assembly 24 andthe bearing block assembly 26 are retained together; thus, no threadsare required for structural purposes in the engine block and the loadsare carried by the studs themselves.

More specifically now and looking to FIGURE 2, the internal combustionengine 20 is of an overhead valve type construction with the cylinderhead assembly 22 comprising a cylinder head 21 and, associated therewithby means known in the art, intake and exhaust valve assemblies,generally designated by the numerals 28 and 30, respectively. The intakeand exhaust valve assemblies 28 and 30 comprise the usual valve, valvespring and rocker arm and are individual to intake and exhaust manifoldassemblies 32 and 34, respectively, which are secured to the cylinderhead 21 in a conventional manner. The rocker arms are rockably securedto a rocker arm bracket support 27 which is attached to the cylinderhead 21 in a manner to be described. Each of the plurality of intakevalve assemblies 28 and exhaust valve assemblies 30 is associated with acorresponding one of a plurality of combustion chambers 38 which aredisposed in the cylinder head 21.

The rocker arms associated with the valve assemblies 28 and 30 aredriven by an overhead cam shaft 36 which, in turn, is driven by theinternal combustion engine 20 by means well known in the art. A coverplate 37 is secured to and covers the top portion of the cylinder headassembly 32, thereby protecting the cam shaft 36, and the associatedintake and exhaust valve assemblies 28 and 30, from dirt, etc. Thecylinder head assembly 22 has a plurality of vertically extending bores29 and 31 which, at their outer extremities, extend through relativelyfiat shoulder portions 33 and 35, respectively (see FIGURE 3). 1

Each of the plurality of combustion chambers 38 is individual to one ofa plurality of cylinder bores 40 disposed in the enginev block assembly24. The engine block assembly 24 is comprised of an aluminum alloyengine block- 42 into which has been cast at its upper end a pluralityof vertically extending cylinder bores 40, since however, the engineblock 42 is constructed of an aluminumalloy, the cylinder bores 40 areprovided with an internal lining 44 of cast iron or some other moredurable metal. It is common practice to cast the cylinder bore 40 aroundthe lining 44.

The engine block 42 has at its upper extremity a generally rectangularlyshaped rim portion 45 terminating in a relatively flat faced surface 46(FIGURE 4) which is matable with a similar planar surface 47 (FIG- URE3) on the cylinder head 21. The upper rim portion 45 has a plurality ofinwardly extending bosses 48 having vertical bores 50 extendingtherethrough. Located interiorly of the engine block 42, and spacedvertically from the fiat faced portion 46 is a flat web portion 52 whichexternally interconnects each of the plurality of cylinder bores 40 andis connected to the rim portion 45. The web portion 52 has a pluralityof holes 54 and slots 56 extending therethrough for a purpose to bedescribed.

The plurality of cylinder bores 40 are also externally interconnected attheir vertically lower extremities by a generally rectangularly shapedlower web portion 58 (FIGURE 1). The web portion 58 is integral with anoutwardly extending semi-circularly shaped crankcase portion 60.Internally, the crankcase portion 60 comprises a plurality of bays 62individual to each of the cylinder bores 40. Each bay is disposedbetween a pair of a plurality of vertically downwardly extending ribportions 64 with each of the rib portions 64 adapted to receive one ofthe plurality of bearing block assemblies 26. The rib portions 64 extendtransversely across the width of the crankcase portion 60 and havelocated therein a pair of vertically extending spaced bores 66 which arein axial alignment with and individual to ones of the plurality of bores50 disposed in the bosses 48 in the upper rim portion 45. Each of thebores 66 have enlarged diameter bore portions 67 for a purpose to bedescribed. On the outside surface of the crankcase portion 60 is locateda plurality of pairs of vertically downwardly extending ribs 68 (seeFIGURE 1) which are substantially disposed in alignment with theinternal rib portions 64- =and hence are in alignment with the locationof the bearing block assemblies 26. These ribs are included to lendstrength and rigidity to the engine block 42. The plurality of pairs ofribs 68 are interconnected by a longitudinally extending rib 70 anddiagonally extending ribs 72. The plurality of pairs of ribs 68 areintegral with inwardly extending boss portions 74 (FIGURES 1 and 3)having a bore 76 extending therethrough for a purpose to be described.

A longitudinally extending slot 78 is cast or otherwise formed in theexternal portion of one side of the web portion 58. A plurality of bores80 communicate the slot 78 with the enlarged bore portions 67 of each ofthe bores 66 on that side of the engine block 42. A pair of thin ribbedwater jacket members 82 are secured to both sides of the engine block 42by means of a plurality of bolts 84 threadably engaged with the upperrim portion 45 and the lower web portion 58. Note that, while the bolts84 are threadably engaged with the aluminum alloy engine block 42, it isnot for the purpose of sustaining loads but simply to secure the thinwater jackets which in the preferred embodiment are made of aluminumalloy, and which, as will be seen, are not structural members. The upperweb portion 52 and the lower web portion 58, along with the water jacketmembers 82, define therein an enclosed chamber for holding the enginecoolant. Looking to FIGURE 1, it can be seen that this chamber providescirculation of the coolant peripherally about the plurality of cylinderbores 40. The portion of the engine assembly 20 above the upper webportion 52 is in fluid communication with the enclosed chamber justdescribed by means of the plurality of holes 54 and slots 56 in theupper web portion 52. Looking now to FIGURE 1, coolant can be pumpedinto the cylinder head assembly 22 by conventional means (not shown)through an inlet pipe 86 and into a passageway 88 disposed in thecylinder head assembly 22. The passageway 88 leads to the usual coolingchambers in the cylinder head assembly 22 for cooling the combustionchambers 38 and is in comrnunication, by means known in the art, withthe enclosed area about the cylinder bores 40 previously described. Thecoolant is exhausted from the above described chambers by means (notshown) back to the water pump (not shown).

The surface 47 of the cylinder head 21 is separated from the mating,planar surface 46 on the rectangular upper rim portion 45 of the engineblock 42 by means of a gasket 90 which prevents leakage of the coolanttherebetween; likewise, a pair of gaskets 92 are inserted between thewater jacket members 82 and the engine block 42 to prevent the coolantfrom leaking therebetween.

The internal rib portions 64 have a thin center portion 94 (FIGURE 3)blending into and integral with thicker outer portions 96 through whichthe bores 66 and 67 extend. The thicker outer portions 96 generallydefine a rectangular opening 98 for matably receiving one of theplurality of bearing block assemblies 26. Each of the bearing blockassemblies 26 comprises an upper bearing block member 100 and a lowerbearing cap member 102 which are retained together in a manner to bedescribed and which define at their ends a generally rectangular shapemat-able with the generally rectangular cavity 98. The bearing blockmember 100 and bearing cap member 102 are made of cast iron or othersimilarly hard and durable material for a purpose to be readilyapparent. The center portion of the upper bearing block 100 and thebearing cap member 102 extends arcuately outwardly. The thin centerportion 94 of the internal rib portion 64 is relieved such that theupper bearing block member 100 engages the upper rib portion 64 only atthe thick outer portions 96.

The upper bearing block member 100 and the lower bearing cap 102 havepairs of aligned bores 104 and 106, respectively, for a purpose to bedescribed. When each of the bearing block assemblies 26 is properlyfitted Within the rectangularly shaped aperture 98, the bores 104 and106 are at axial alignment wit-h the bores 67 and 66 in the thick outerportion 96 of the internal rib portion 64 and are therefore also inalignment with individual ones of the plurality of bores 50 in the upperrim portion 45 and with individual ones of the bores 29 and 31 in thecylinder head 21.

Disposed in each of the bores in the plurality of hearing blockassemblies 26 and in the engine block 42 which are in alignment with andindividual to one of the bores 29 in the cylinder head 21 is a stud 108(FIGURE 3). Disposed in each of the bores in the plurality of bearingblock assemblies 26 and the engine block 42 which are in alignment withand individual to the bores 31 in the cylinder head 21 is anothersimilarly constructed stud 108'. The studs 108 and 108' are threaded atthe opposite extremities 112, 114 and 112', 114, respectively.

The stud 108 has a first shank portion of a diameter less than that ofthe bore 29 and passes through the bore 29 and terminates therein in anenlarged diameter portion 122 which is of substantially the samediameter as the bore 29. The enlarged diameter portion 122 is located atthe juncture between the rocker arm bracket support 27 and the topportion of the cylinder head assembly 22 such as to provide a seal atthat juncture. The remainder of the stud 120 at that end passes througha bore 124 in the rocker arm bracket support with the threaded portion112 extending partially outwardly therefrom. The other end of the shank120 terminates in an enlarged head portion 126 which bears against thethicker outer portion 96 of the internal rib portion 66. The enlargedhead portion 126 can be provided with a plurality of peripheral faces tobe matable with a similarly faced groove or recess in the top surface ofthe internal rib portion 64 thereby preventing any tendency for rotationof the stud 108. Extending from the head portion 126 is a second shankportion 128 which is matable within the bore 66 and extends through thebore 67. The diameter of the bore 67 is somewhat larger than that of theshank portion 128, thus leaving a space therebetween for a purpose to bedescribed. The shank portion 128 also extends through the bores 104 and106 in the upper bearing block 100 and in the lower bearing cap 102,respectively, and has an enlarged diameter portion 130 which is disposedat the juncture of the upper bearing block member 100 and the lowerbearing cap member 102, thereby closing off at that point thecommunicating bores 67 and 104, since the portion 130 is substantiallyof the same diameter as the bores 104, 106. The threaded portion 114extends outwardly partially beyond the lower bearing cap member 102. Anut 116 engageable with the threaded portion 114 is tightened against awasher 132 and hence against the lower bearing cap member 102 andprovides a clamping force with the enlarged head portion 126, therebysecurely clamping the individual ones of the bearing block assemblies 26to the rectangular aperture 98 of the internal rib portion 64. Likewise,a nut 136 is threadable on the threaded end 112 against a washer 138 andthereby secures the rocker arm bracket support 27 to the cylinder head21 which in turn then is secured to the upper rim portion 45 of theengine block member 42. A plurality of studs 141 are also used to securethe rocker arm bracket support 27 to the cylinder head assembly 22 butthese studs are not used to carry any appreciable load.

In a similar manner, the stud 108 has a nut 116 engageable with thethreaded portion 114 and tightened against a washer 132' and henceagainst the lower bearing cap member 102 for providing a clamping forcewith an enlarged head portion 126 to further secure the individual onesof the bearing block assemblies 26 to the rectangular aperture 98 of theinternal rib portion 64. Likewise, a nut 136' is threadable on thethreaded end 112 against a washer 138- and thereby further secures thecylinder head 21 to the upper rim portion 45 of the engine block member42. As with the stud 108, the stud 108 has an enlarged diameter portion130" matably disposed in the bores 104, 106 at the juncture of the upperbearing block member 100 and the lower bearing cap member 102.

Each of the lower bearing cap members 102 has a pair of horizontallyextended threaded bores 140 in alignment with the bores 76 in the bossportions 74. The threaded bores are engageable by a plurality of studs142 passing through bores 76, each of which has a head portion hearingagainst the boss portions 74 via lock washers 144 to further secure thebearing block assemblies 26 within the rectangular aperture 98 in theinternal rib portions 64. The studs 142, by being so located, preventthe crankcase portion 60 from flexing outwardly, due to horizontal loadcomponents on the associated crankshaft.

Note that in the construction just described, while the studs 108 and108 react the vertical engine load components, there is no threadedengagement anywhere with the aluminum engine block 42 or any aluminumalloy member in which a component of the engine load is to be reacted.Also note that, since the load is substantially taken by the studs 108and 108, the water jacket members 82 and also the walls of the cylinderbores 80 can be constructed of thin gauge, thereby providing a saving inmaterial. Note that even the side loads on the crankshaft, while reactedagainst the aluminum crankcase, are not reacted through threads in thealuminum crankcase portion 60 but rather through threads in the lowerbearing cap member 102 which is made of a stronger material, such ascast iron.

Each of the bearing block assemblies 26 has disposed therein a mainbearing 143 for rotatably holding a journal 145 of a crankcase 146.Secured to each of the throws 148 of the crankshaft 146 is a pistonassembly 150 (FIGURE 2) which is of a conventional construction andcomprises a piston head having the usual oil and pressure rings,connected to the small end of a connecting rod by a wrist pin, with theenlarged end of the connecting rod bearing connected to one of thethrows of the crankshaft by means of a connecting rod cap and bearinginserts. An oil pan member 154 (FIGURE 3 is bolted by a plurality ofbolts 156 and associated washers 158 to a fiat face 160 at the bottomextremity of the crankcase portion 60 with a gasket member sandwiched inbetween to provide a seal.

In order to provide lubrication to the main bearings 143, thetransversely extending .slot 78 is connected to the oil supply system(not shown) provided by means well known in the art. The enlarged bore67 is in communication with the slot 78 via the bore 80, thereby,providing an oil passageway to the upper bearing block memher 100. Thismember is provided with a bore 172 which connects the bore 67 to themain bearing 143. Since the bore 67 is larger than the diameter of theshank 128 of stud 108, oil can pass from the oil pump through the oilgallery 78 throughthe bore 80, through the gap between thebore 67 andthe shank 128, through the bore 172 and thence to the main bearing 142.Note that all of the passageways described save for the bore 172 in theupper bearing block member 100 can be cored within the engine block 42,thus eliminating the need for machining. The slot 78 forms the oilgallery by means of the water jacket member 82 located on the open sideof the slot; a seal is providedtherebetween to prevent leakage.

Thus the internal combustion engine assembly20, as described, providesan engine block member 42 which requires only a minimum of machining andprovides a construction in which not load-carrying connections are madeby means of threads in the aluminum alloy engine block 42; also thewater jacket members 82 and the walls of the cylinder bores 40 can bemaintained thin, since the load is carried by the plurality of studs 108and 108'.

The aluminum alloy engine block 42, as previously discussed, can beformed by a novel method and apparatus as shown in the FIGURES 5 and 6.It is customary in the die casting of aluminum engine blocks to form thecylinder bores and the water jacket by pulling theassociated die fromthe top of the bores. The cylinder block 42 as shown and previouslydescribed, however, can be die cast by pulling the dies forming thecylinder bores and the water jacket area from the sides. By die castingthe block 42 .by the latter method, the walls of the cylinder bores canbe cast thinner and also, thinner, separate water jackets 82 can beprovided.

Looking now specifically to FIGURES 5 and 6, an upper slide and a lowerslide 182 define the outer configuration of the cylinder bores 40 andthe crankcase portion 60 with its associated ribbing; the oil galleryslot 78 with the associated apertures 80 and the bores 76 for receivingthe plurality of studs 142 (FIGURE 3) are cored in the upper and lowerslides 180 and 182, respectively. A stationary die section 184cooperates with an ejector die section 186 to define the remainder ofthe die cast aluminum engine block 42. The stationary die section 184,which defines the internal portion of the engine block 42, has securedto it a die mandrel portion 188 on which is located the internalcylinder bore lining 44. The mandrel 188 posit-ionally locates thelining 44 and cooperates with the upper slide 180 and the lower slide182 to define the plurality of cylinder bores 40. The bore liner 44 ofcast iron or the like is keyed in the proper position by means of keys190 on the die mandrel 188. In the stationary die section 184 means areprovided to core the bore 66 and the enlarged bore 67 which extendthrough the internal rib portion 64. The rectangularly shaped apertureor cavity 98 is also defined by the stationary section 184. The ejectordie section 186 defines the upper rim portion 45 (FIGURE and, to 'getherwith the stationary die section 18 4, defines the upper web portion 52While coring the holes 54 provided therein for coolant circulation. Theejector die section 186 also defines the plurality of bosses 48 and hascored therein the bores 50 extending therethrou-gh.

In die casting the cylinder block as shown in FIG- URES 5 and 6, thealuminum alloy is forced under pressure through a shot tube or gate,generally indicated by the numeral 189, until the cavity between theupper slide 180, the lower slide 182, the stationary die section 184 andthe ejector die section 186 is filled. On completion of the operation,.the upper and lower slides 18%) and 1 82 are parted and the ejector diesection 186 is moved outwardly, leaving the die cast aluminum engineblock 42.

In addition to the other advantages previously enumerated, anotheradvantage of die casting an engine block by pulling the dies and henceforming the cylinders from the sides, as described, is that the coolingpassageways can be made to extend literally completely around theperiphery of the cylinder bores 40.

Some of the features of this invention are equally applicable to a diecast aluminum alloy block in which the cylinder bores and water jacketshave been cast by pulling the die out from the top.

Looking now to FIGURE 7, a modified internal combustion engine assembly20a is shown in which components similar to those in the previouslydiscussed embodiment, as shown 'in FIGURES l4, are given similar numberswith the addition of the suffix a. Thus the internal combustion engineassembly 20a comprises a cylinder head assembly 22a, an engine blockassembly 24a and a plurality of bearing block assemblies 26a secured orclamped together by a plurality of studs 108a and 108a. The studs 108aand 108a have enlarged diameter threaded portions 126a and 126a,respectively, intermediate their ends upon which are secured a pair ofnut :and lock washer assemblies 192 and 192', respectively.

The engine block assembly 24a includes an aluminum alloy die cast engineblock 42a which has integrally die cast water jacket walls 82a. Thewater jacket walls 82a terminate in an upper rim portion 45a (FIGURE 8)which has cast or cored therein a plurality of bores a through which thestuds 108a and W301 pass. Integrally with the engine block 42a are aplurality of cylinder bores 40a having cast therein liners 44a of castiron or some other similar material. The plurality of cylinder bores 40aare externally connected at their vertically lower extremities to agenerally rectangularly shaped web portion 58a which is integral with acrankcase portion 60a of the block 42a. Adjacent ones of the cylinderbores 40a are interconnected by vertically extending rib portions 58a.Each of a plurality of transverse rib portions 64a in the engine block42a define a recess 98a for matably receiving that one of the pluralityof bearing block assemblies with which it is individual.

In the embodiment shown in FIGURES 7 and 8, since there is no webportion connecting the cylinder bores 46a at their upper ends similar tothe web portion 52, (FIG- URE 4) of the first embodiment, the water orcoolant is free to circulate around the bores 48 without the necessityof holes and slots 54 and 56, respectively. However, note that with thevertical rib portion 58a, the coolant cannot circulate as completelyaround the periphery of the bores 40a in the block 42a as was possiblewith the previously discussed embodiment.

The studs 108a and 108a have threaded portions 112a, v

114a and 11411, respectively. When these have been tightened down andthe nut and lock washer assemblies 192 and 192, respectively, have beensecured, the engine assembly 20a is then thereby held or clampedtogether. Thus, as in the previously described embodiment shown inFIGURES 1-4, the vertical loads occurring within the engine assembly 20aare not taken by any threaded connection with the die cast aluminumalloy engine block 42a, but rather by the studs 108a and 108a.

Since the water jackets 8 2a are cast integrally with the engine block42a, the oil gallery 78a is longitudinally cored completely within theengine block 42a. In this construction, the enlarged bore 67a throughwhich the stud 108a passes is not used for the oil passageway but aseparate passageway 194 is cored to communicate with the longitudinalpassageway 78a. Each of the bearing block assemblies 26a is similar tothe bearing block assembly 26 of FIGURES 14 and comprises an upperbearing block member 10% and a lower bearing cap 162a for holding a mainbearing member 143a. A pair of back-to-back counter-bores in the bearingblock member liitia and bearing cap 102a define a chamber 104a throughwhich a portion of the stud 108a passes in clearance relationship. Agroove 198 in that face of the upper bearing block a mating with thebearing cap 102a communicates the main bearing 143a with the bore 194via the chamber 104a and a vertically extending groove 1% in the bearingblock 100a which is in alignment with the bore 194. Thus, each of themain bearings 143a can be lubricated by means of the oil gallery 78a andthe respective bores 194, grooves 196 and 1% and chambers 104a.Similarly to the embodiment shown in FIGURES 1-4, each of the bearingblock assemblies 26a is further maintained within the recess 98a in thetransverse rib portion 64a by means of bolts 142a extending throughbores 76a in boss portions 74a and threada'bly engaging the bearingblock assemblies 26a. Note again that in respect to the aluminum alloyengine block 42a, the oil passageways can all be cored, therebyeliminating the need for any machining. Since the rest of the structureof the engine assembly 20a is similar to that as shown in FIGURES l-4and as previously described, the remaining portions will not bedescribed here.

The structure of the engine block 42a shown in FIGURES 7 and 8facilitates casting of the water jacket 82a and the cylinder bores 40aby pulling the die forming that structure out from the top rather thanfrom the sides as with the embodiment shown in FIGURES 14.

Looking now specifically to FIGURES 9 and 10, an upper slide 18% and alower slide 182a define the outer configuration of the water jackets 82aand the crankcase portion 66a with its associated ribbing and have coredtherein the bores 76a for receiving the plurality of studs 142a (FIGURE7). A stationary die section 184a cooperates with an ejector die section186a to define the remainder of the die cast aluminum alloy engine block42a. The stationary die section 184a which defines the internal portionof engine block 42a has secured to it a die mandrel portion 188a onwhich is located the internal cylinder bore lining 44a; thus the mandrel188a, along with the bore liner 44a of cast iron or the like, definesthe diameter of the cylinder bore 40a. The die section 184a also coresthe plurality of vertically extending enlarged bores 67a through whichthe studs 108a and 108a extend as well as the vertical bores 194 incommunication with the longitudinally extending oil gallery 78a which iscored separately by a coring rod 202. The ejector die section 186adefines the internal configuration of the water jackets 82a and also theexternal diameter of the cylinder walls 40a. The upper and lower slidesa and 1821: also define the upper rim portion 45a while the ejector diesection 186a cores the plurality of holes 50a through which theplurality of studs 108a and 108a extend.

In die casting the cylinder block 42a as shown in FIGURES 9 and 10, thealuminum alloy is forced under pressure through a shot tube or gategenerally indicated by the numeral 189a until the cavity between theupper slide 180a, the lower slide 182a, the stationary die section 184aand the ejector die section 186a is filled.- On completion of theoperation, the upper and lower slides 180 and 182 are parted and theejector slide 18611 is moved outwardly. The rod 202 used to core thelongitudinal bore 78a forming the oil gallery is then removed, thusleaving the die cast block 42a.

Still another modification of the engine assembly as shown in FIGURES1-4 is shown in FIGURE 11. In this modification, components servingsimilar functions to like components of the embodiments shown in FIG-URES 1-4 are given similar numbers with the suflix 11 added.

Looking now to FIGURE 11, an internal combustion engine assembly 20bcomprises a cylinder head assembly 22b, an engine block assembly 24b,and a plurality of bearing block assemblies 26b, all vertically joinedor clamped together in a sandwichtype arrangement by means of aplurality of studs. Instead of utilizing single studs similar to 108 and108' to extend vertically through the engine assembly as shown in theembodiment depicted in FIGURES l-4, pairs of studs 108b, 1083 and 108b,108B, respectively, are used. 'Ihus the studs 108b and 108b secure thecylinder head assembly 22b to the engine block assembly 42b while thestuds 108B and 108B secure each of the bearing block assemblies 26b tothe engine block 42b.

The engine block 42b has an upper rim portion 45b in which the thicknessand hence the strength of the bosses through which the studs 108b and108b extend has been increased in order to accommodate the load nowapplied thereto. Thus the cylinder head assembly 22b is secured to theengine block 42b of the block assembly 24b by means of nuts 136b, 136b',and the associated washers, threaded on one end of studs 108b and 108b,respectively, and by means of nuts 200, 200' and the associated washers,threaded on the opposite end of studs 10812 and 108b. Each of thebearing block assemblies 26b is secured or clamped to the engine block42b by means of the studs 108B and 108B which extend through in-linebores in the transverse rib portion 64b and in that one of the bearingblock assemblies 26b with which it is individual and by means of nut andlock washer assemblies 192b and 192k threaded on one end of the studsand in engagement with external shoulders 204 on the transverse ribportion 64b and nuts 116 b and 11Gb threaded on the other end of thestuds and bearing against that bearing block assembly 26b.

Note also in the construction as shown in FIGURE 11 that no loadcarrying connection is made by means of threads Within the aluminumalloy die cast aluminum engine block 42b. The provision for the oilgallery 78b and for communication therefrom to the main bear- .in-g 143bis similar to that as shown and described with reference to theembodiment shown in FIGURE 7. In general then, the structure of theengine block 42b shown in FIGURE 11 is similar to that as shown in FIG-URE 7 and could be cast by a method and apparatus similar to thatdescribed in conjunction with FIGURES 8 and 9.

While it will be apparent that the preferred embodiments of theinvention disclosed are well calculated to fufill the objects abovestated, it will be appreciated that the invention is susceptible tomodification, variation and change without departing from the properscope or fair meaning of the su-bjoined claims.

We claim:

1. The method of die-casting an engine block of a lightweight metalcomprising a plurality of in-line vertically upwardly extending cylinderbores each having a cylindrical cast iron sleeve secured therein, anupper rim portion having a plurality of bores therethrough and connectedto an upper portion of each of said cylinder bores by a web portion, alower web portion externally connecting each of said cylinder bores at alower portion thereof, an outwardly extending crankcase portion integralwith said lower web portion, a plurality of transversely steps oflocating the plurality of cast iron sleeves on to w a plurality ofmandrels secured to a stationary die section, the stationary die sectiondefining the internal configuration of the crankcase portion and havingmeans for coring each pair'of spaced bores in each of the lower ribportions, disposing an upper and lower slide die section oppositely andproximate to the stationary die section to define the outerconfiguration of the crankcase portion and to define the outerconfiguration of each of the plurality of cylinder bores, one of theslide die sections having means for coring the longitudinally extendingslot and plurality of passageways interconnecting the slot with thespaced bores on that side, disposing an ejector slide die sectionproximate to the upper and lower slide die sections to define therewiththe upper rim portion and to core therethrough the plurality of bores,and injecting molten lightweight metal into the cavity defined by thestationary die section, the upper and lower slide die sections and theinjector slide die section to form the engine block.

2. The method of die-casting an engine block of lightweight metalcomprising a plurality of in-line vertically upwardly extending cylinderbores and an upper rim portion connected to an upper portion of each ofsaid cylinder bores, said method comprising the steps of locating astationary die section having a plurality of mandrels thereon between anupper and lower slide die section such that the cavity between themandrels and slide die sections defines the plurality of cylinder bores,locating an ejector slide die section proximate the upper and lowerslide die sections to define therewith the upper rim portion, andinjecting molten lightweight metal into the cavity defined by thestationary die section, the upper and lower slide die sections and theinjector slide die section to form the engine block.

3. The method of die-casting an aluminum alloy engine block comprising aplurality of in-line vertically upwardly extending cylinder bores eachhaving a cylindrical cast iron sleeve secured therein, a pair ofvertically upwardly extending water jacket walls disposed on oppositesides of said plurality of said cylinder bores, an upper rim portionhaving a plurality of bores therethrough and connected to said waterjacket walls, a lower Web portion externally interconnecting each ofsaid cylinder bores at a lower portion thereof, an outwardly extendingcrankcase portion integral with said lower web portion, a plurality oftransversely extending lower rib portions disposed in said crankcaseportion each defining a recess at its lower extremity and each having apairof spaced bores extending vertically therethrough, each of saidspaced bores being individual and in axial alignment with one of saidplurality of bores in said upper rim portion, one side of said engineblock having a longitudinally ill the stationary die section definingthe internal configuration of the crankcase portion and having means forcoring each pair of spaced bores and the vertical bores in each of thelower rib portions, coring the longitudinally extending bore such thatit is in communication with each of the vertical bores, disposing anupper and lower slide die section oppositely and proximate to thestationary die section to define the outer configuration of thecrankcase portion, disposing an ejector slide die section proximate tothe upper and lower die sections to define therewith the upper rimportion and to core therethrough the plurality of bores, the ejectorslide die section having means cooperating with the upper and [lowerslide die sections to define therebetween the water-jacket walls andcooperating with the man-drels having the cast iron sleeve thereon todefine therebetween the cylinder bores, and injecting molten aluminumalloy into the cavity defined by the stationary die section, the upperand lower slide die sections and the injector slide die section to formthe aluminum alloy engine block.

4. The method of die casting an engine block having a plurality ofinline, outwardly extending cylinder bores comprising the steps offorming the radially inner surface of the cylinder 'bores by coaxiallyextending members and forming the radially outer surface of the cylinderbores by a pair of oppositely located dies movable transversely relativeto the axis of the cylinder bores.

5. The method of die casting an engine block comprising a plurality ofin-line vertically, upwardly extending cyilinder bores and an upper rimportion connected to an upper portion of each said cylinder bores, saidmethod comprising the steps of forming the upper surface of the upperrim portion and the radially inner surface of the cylinder bores by astructure having members extending ooaxially With the cylinder bores andby forming the radially outer surface of the cylinder bores byoppositely located dies movable transversely relative to the axis of thecylinder bores.

6. The method of die casting an engine block comprising a plurality ofin-line, vertically extending cylinder bows and an upper rim portion ofeach of said cylinder 'bores, said method comprising the steps offorming the upper surface of the upper rim portion and the radiallyinner surface of the cylinder bores by a structure having members eachincluding a cast iron sleeve extending coaxially with the cylinder boresand by forming the remainder of the upper rirn portion and the radiallyouter surface of the cylinder bores by a pair of oppositely located diesmovable transversely relative to the axis of the cylinder bores.

References Cited by the Examiner UNITED STATES PATENTS 1,769,456 7/1930Pickering 22-200 2,783,510 5/1957 Dolza et al 22-13l 2,831,225 4/1958Kolbe et al. 2213l OTHER REFERENCES Die Casting, by Herb, 2nd ed., pu-b.1952, pp. 136-.

I. SPENCER OVERHOLSER, Primary Examiner.

MARCUS U. LYONS, Examiner.

E. MAR, Assistant Examiner.

4. THE METHOD DIE CASTING AN ENGINE BLOCK HAVING PLURALITY OF IN-LINE,OUTWARDLY EXTENDING CYLINDER BORES COMPRISING THE STEPS OF FORMING THERADIALLY INNER SURFACE OF THE CYLINDER BORES BY COAXIALLY EXTENDINGMEMBERS AND FORMING THE RADIALLY OUTER SURFACE OF THE CYLINDER BORES BYA PAIR OF OPPOSITELY LOCATED DIES MOVABLE TRANSVERSELY RELATIVE TO THEAXIS OF THE CYLINDER BORES.